Sintered bearing for fuel pump and method of manufacturing same

Patent metadata

Field	Value
Publication number	US-2016223018-A1
Application number	US-201414914164-A
Country	US
Kind code	A1
Filing date	Aug 25, 2014
Priority date	Aug 27, 2013
Publication date	Aug 4, 2016
Grant date	—

Abstract

Provided is a sintered bearing ( 1, 2 ) for a fuel pump, including raw material powder including 8.5% by weight to 10% by weight of aluminum, 0.1% by weight to 0.6% by weight of phosphorus, and the balance including copper as a main component, and inevitable impurities. The sintered bearing ( 1, 2 ) has a structure of a sintered aluminum-copper alloy, and has a pore formed in a surface layer portion of the sintered bearing, which is smaller in size than an internal pore of the sintered bearing.

First claim

1 . A sintered bearing for a motor-type fuel pump, comprising raw material powder comprising 8.5% by weight to 10% by weight of aluminum, 0.1% by weight to 0.6% by weight of phosphorus, and the balance comprising copper as a main component, and inevitable impurities,
the sintered bearing having a structure of a sintered aluminum-copper alloy, the sintered bearing having a pore formed in a surface layer portion of the sintered bearing, the pore being smaller in size than an internal pore of the sintered bearing.

2 . The sintered bearing for a motor-type fuel pump according to claim 1 , wherein the structure of the sintered aluminum-copper alloy comprises an α-phase.

3 . The sintered bearing for a motor-type fuel pump according to claim 1 , wherein a ratio γ-phase/α-phase of a γ-phase and the α-phase of the structure of the sintered aluminum-copper alloy is set to 0<γ-phase/α-phase≦0.10.

4 . The sintered bearing for a motor-type fuel pump according to claim 1 , wherein the sintered bearing has added thereto 3% by weight to 10% by weight of graphite with respect to a total of 100% by weight of the raw material powder comprising the aluminum, the phosphorus, and the balance comprising the copper as the main component, and the inevitable impurities.

5 . The sintered bearing for a motor-type fuel pump according to claim 1 , wherein the sintered bearing for a motor-type fuel pump is free of tin to be added as a sintering aid.

6 . The sintered bearing for a motor-type fuel pump according to claim 1 , wherein a content of the aluminum is set to from 9% by weight to 9.5% by weight.

7 . A method of manufacturing a sintered bearing for a fuel pump,
the sintered bearing comprising raw material powder comprising 8.5% by weight to 10% by weight of aluminum, 0.1% by weight to 0.6% by weight of phosphorus, and the balance comprising copper as a main component, and inevitable impurities, the method using aluminum-copper alloy powder, electrolytic copper powder, and phosphorus-copper alloy powder as the raw material powder, the method comprising at least: a molding step of molding a green compact having a sintering aid added to the raw material powder; a sintering step of obtaining, from the green compact, a sintered compact having a structure of an aluminum-copper alloy; and a sizing step of subjecting the sintered compact to dimension shaping.

8 . The method of manufacturing a sintered bearing for a fuel pump according to claim 7 , wherein the sintered bearing has added thereto, as the sintering aid, a total of 0.05% by weight to 0.2% by weight of aluminum fluoride and calcium fluoride with respect to a total of 100% by weight of the raw material powder comprising the aluminum-copper alloy powder, the electrolytic copper powder, and the phosphorus-copper alloy powder.

9 . The method of manufacturing a sintered bearing for a fuel pump according to claim 7 , wherein a ratio d 2 /d 1 of a mean grain diameter d 1 of the aluminum-copper alloy powder and a mean grain diameter d 2 of the electrolytic copper powder is set to from 2 to 3.

10 . The method of manufacturing a sintered bearing for a fuel pump according to claim 7 ,
wherein the electrolytic copper powder comprises powders having different shapes, and wherein a ratio W 2 /W 1 of a proportion W 1 of the electrolytic copper powder having an aspect ratio of 2 or more and a proportion W 2 of the electrolytic copper powder having an aspect ratio of less than 2 is set to from 3 to 9.

11 . A method of manufacturing a sintered bearing for a fuel pump,
the sintered bearing comprising raw material powder comprising 8.5% by weight to 10% by weight of aluminum, 0.1% by weight to 0.6% by weight of phosphorus, and the balance comprising copper as a main component, and inevitable impurities, the method using aluminum-copper alloy powder and phosphorus-copper alloy powder as the raw material powder without adding powder of a copper simple substance to the raw material powder, the method comprising at least: a molding step of molding a green compact having a sintering aid added to the raw material powder; a sintering step of obtaining, from the green compact, a sintered compact having a structure of an aluminum-copper alloy; and a sizing step of subjecting the sintered compact to dimension shaping.

12 . The method of manufacturing a sintered bearing for a fuel pump according to claim 11 , wherein the aluminum-copper alloy powder serving as the raw material powder comprises 7% by weight to 11% by weight of aluminum-copper alloy powder.

Assignees

• Ito Yoshinori
• NAGATA Hiroharu
• Ohashi Yuta
• Seto Tomoyuki
• Ntn Toyo Bearing Co Ltd

Inventors

• Ito Yoshinori
• NAGATA Hiroharu
• Ohashi Yuta
• Seto Tomoyuki

Classifications

• C22C1/08

  Alloys with open or closed pores · CPC title

• F16C33/145 Primary

  of sintered porous bearings · CPC title

• B22F2302/40

  Carbon, graphite · CPC title

• B22F3/1146

  After-treatment maintaining the porosity (B22F3/114 takes precedence) · CPC title

• F16C33/128

  Porous bearings, e.g. bushes of sintered alloy · CPC title